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VGA resistor substitutions? — Parallax Forums

VGA resistor substitutions?

CJCJ Posts: 470
edited 2006-06-06 18:20 in Propeller 1
Would it be possible to use either 220s or 270s in place of the 240s for the VGA interface?

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Who says you have to have knowledge to use it?

I've killed a fly with my bare mind.

Comments

  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2006-06-06 14:25
    Cj,

    It would probably work just fine, but consider with either one that your going to be about %10 out of spec.
    If your are using 10% tolerance resistors to begin with, you have a potential to be out by as much as 20%
    or right on the money depending on which way they lean. In this situation, I would probably hand pick the
    values so that they are at least within 5% (228 to 252).

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    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • CJCJ Posts: 470
    edited 2006-06-06 17:01
    built it up on some perfboard with 5% 220s works beautifully with Chip's new high res vga demo

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    Who says you have to have knowledge to use it?

    I've killed a fly with my bare mind.
  • Kaos KiddKaos Kidd Posts: 614
    edited 2006-06-06 18:20
    I had nothing in the 210~250 range, so I went and got 10 turn 1K pots, dialed them in to 240 and it's sweet.
    I was playing around with them, and while I was only running the vga_text object, I didn't get noticable change until < 210 or > 270.

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    Just tossing my two bits worth into the bit bucket


    KK
    ·
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